Dellorto SSI Choke

[Bevel bob]

After going through all my data on the SSI, (non of which actually refers to the SSI29D!) ,I think its clear that the enrichment device was never intended to be used as a cold start choke but as a general purpose enricher for tuning, not really much use to me as it appears all my problems have been from being too rich anyway.Does anyone know what the "D" stands for??.

[Jordan]

D for destro, meaning right.
S stands for sinestro, meaning left.

[Bevel bob]

AHH, we learn something every day, thanks.

[JasonB]

Yeah never to old to learn new things , call me silly, but I am determine to use a SSI and have spent allot of time trying to get my bike to tick over(idle) nicely with a Dellorto, big cam, big valved head, which for me was more to do with the remote fuel height adjustment, but this is all the fun playing with these beautiful little Italian bikes. I bought from ebay a 29mm S and the choke insert was badly corroded so I am looking at getting some CNC machined, I think if I am correct you could then turn a 27mm into a 29mm???? If anyone is interested in this as more made better price drop me a email.

IMG_0654.jpg

[Bevel bob]

It would be nice if we could get the body bored and sleeved to take a new or re machined and chrome plated slide as is done for the Amals.

[JasonB]

I was talking to Phil@ Road and Race a couple months back and he said he can get this done.

Regards
JasonB

[Rick]

I'm with JasonB on this- the effort to get an SSI working well will be worth it. So, first, I haven't done any of these procedures, but I plan to test this stuff out someday. This guy bores Amal carb bodies and then shrinks a sleeve over the slide:
http://www.amalsleeve.com/page2.html
I've often wondered about Nikasil coating a carb body- Nikasil is probably a brand name, it's nickel silicon carbide, but most modern aluminum cylinders are coated with it. These guys do it:
http://www.mt-llc.com/
I think a really round body with a nice fitting, really round slide, would be a good start to a good carb. A hard anodized slide would probably work fine too. And there are lots of piston coatings that may be useful:
http://www.jepistons.com/TechCorner/PistonCoatings.aspx
Modern material may be able to improve these old carbs. Before I go to a sleeve- either the slide or the bore- I think I'll try a modern coating after getting the parts nice and round.
Again, no experience with these processes, but they seem promising.

[Bevel bob]

I think its better by far to get the carb body back to standard size so in the future you can use a standard( or refurbished) slide.

[MotoMike]

Does anyone have cut away diagrams of this carburetor. I'm not sure I'm looking at the right carb. Does the SS1 have an idle circuit? I see the SSA and SSB do, and they look a lot like the SS1, but couldn't see what I thought was a mix adjust for the low speed circuit on the SS1 exploded view.

In racing engines (automotive) I have been around with big intakes and carbs, big cams and big valves, they just won't idle because they are optimized to run at or near WFO. I had a warmed over mustang once that needed to idle at 1200 RPM when stock was 700 or so.

If the SS1 is really a racing carb and you are running it on a bike with lumpy cam and big intake, you might be asking too much to expect it to idle nicely. expecially if it has no idle circuit.

[Bevel bob]

It does have an idle jet ,but for the reasons you have listed ,its not good, a bit too much advance on the timing and it will stop with a splutter.this bike is not good in traffic.